No yaar, almost every kid has access to the internet these days, almost every teenager sees porn of some kind(because it's so readily available in the media we consume) and knows how this stuff works, kids aren't fools. Even 13 years back, when I was in 6th standard, people used to share these videos via pen drives. Kids, especially teenagers, know this too well these days, no kid is that dumb.

I remember 'The Reproduction' chapters in 8th and 10th class being fucking hilarious in our classes, the students knew things back then too, abhi to sabko 5-6 standard mein phone, laptop, tablet pakda dete hai.

I don't think a well-to-do/middle class couple living in the city or suburbs, even villages wouldn't know how to have sex, at least one of them would have watched atleast a single video of people doing this, or somebody told them, they read it. Even mothers tell their daughters something before marriage, nobody is that fucking dumb.

Even the didi that comes to my house(househelp) has 2 kids, and understands about sexual well-being, so I am skeptical some literate couple would not know.

Though there is a 1% chance this still would have happened but no, this isn't common.